Earplug



FIG. 1 is a perspective view of an earplug showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is an elevation view thereof, the opposite side being a mirror image; and,

FIG. 4 is a bottom plan view thereof.

The broken lines shown in the drawings are for environmental purposes only and form no part of the claimed design. 

The ornamental design for an earplug, as shown and described. 